Type | Working Paper |
Title | A comparison of internal migration age profile smoothing methods |
Author(s) | |
Publication (Day/Month/Year) | 2012 |
URL | https://gpem.uq.edu.au/qcpr-docs/QCPR_WP_2012_01.pdf |
Abstract | Despite persistent regularities in migration age patterns, data noise arises when migration data are disaggregated by single-year age groups or derived from small-sized samples, requiring observed data to be smoothed. This paper proposes a one-step non-parametric kernel modeling approach to smooth age-specific migration data, and seeks to evaluate its performance against conventional smoothing techniques, both parametric (model schedules) and non-parametric (cubic splines). Model schedules impose a proto-typical age profile of migration, and both model schedules and cubic splines require iterative fitting. Drawing on the age profiles of 28 countries, the paper establishes through residual analysis that one-step kernel regressions better captures the underlying structure of migration than conventional iterative smoothing methods. Application of kernel regressions to migration in Chile since 1970 reveals significant shifts in the age-structure of migration concealed by model schedules. |